ciiadwick



(No Model.)

0. W. OHADWIOK.

ENGINE VALVE GEAR.

No. 561,696. Patented June 9, 1896.

V2 52? 8S. Invenior,

3 9 1; h'C/mfzwiciz, ,7 J is izome AN DREW EYGKAHAM PHDTO-VILMQWASMNGTOMD C UNITED STATES PATENT EEicE.

CYRUS XV. CIIADlVICK, OF CLIFTONDALE, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO GLARENCE COATES, OF SAME PLACE.

ENGINE VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 561,696, dated June 9, 1896. Application filed February 13,1896. Serial No. 579,120. (No model.)

To all whom it may concern:

Be it known that I, CYRUS XV. GHADWIOK, a citizen of the United States, residing at Cliftondale, in the county of Essex and State of Massachusetts,have invented certain new and useful Improvements in Steam-Engine Valve- Gears, of which the following is a specification.

My invention relates to steam-engine valvegears, and especially to that class of valvegears in which the valves are operated by the motion of a wrist-plate, which wrist-plate is given an oscillatory movement by means of an eccentric on the engine shaft. In this type of engine the cutting oft of the steam is effected by releasing a weight at the proper instant, the said weight being in operative connection with the rotating valves. Itis to this particular type of valve-gear, known as the drop cutoff valve-gear, that my invention is applicable.

The objects of my invention are to provide means for securing the most economical distribution of steam within the cylinder of the engine, to prevent any abnormal increase in the speed of the engine, and to automatically stop the. engine in case of the breakage of the governor-belt or other means by which the governor is driven.

My invention consists of the combination, with an en gine-cylinder, two steam-valves and two exhaust-valves, a wrist-plate for operating said valves, means for giving to this wrist-plate an oscillatory or rocking motion, and a governor of the fly-ball or similar form, of a shaft operatively connected to the said governor in such manner as to turn the shaft in opposite directions as the speed increases or decreases, respectively, two cams attached to the said rocking shaft, two levers pivotally connected to the said wrist-plate, each bearing a catch or hook for opening the stean1-valves,a11d two swinging fulcru ms for the said levers, the said fulcru ms being pivotally connected to the said cylinder and moved by the said cams.

In the drawings which illustrate the invention, Figure 1 is a view of all the parts of my invention properly assembled. Fig. 2 shows more clearly the latch which is rigidly connected to the stem of the steam-valves and by which the said valves are opened. Fig. 3 is a view of the governor, showing the means whereby the rocking motion of the cam-shaft is produced. Fig. 4 is a side view of the parts shown in Fig. 3.

In the drawings, A represents the cylinder of the engine.

B and B are the projecting stems of the steam-valves.

G and O are the projecting stems by which the exhaust-valves are moved by the cranks c and c and the links d and cl.

D represents the shaft about which the wrist-plate E is turned with an oscillatory motion by means of the rod F.

G and G are cams rigidly attached to the shaft H and which by their motion move the fulcrums I and I of the levers J and J.

b and 17 represent the latches which engage with the hooks j and j of the levers .I and J.

c and e are the cranks by which the steamvalve stems are brought to the normal position, as shown, by the action of the weights K and K and the rods k and 7c. K and K are retarded at the lower part of their motion by the dash-pots L and L.

M represents the usual form of fly-ball governor, to the lower part of which is attached the wheelshaped part N, which rises and falls as the speed of the governor increases or decreases.

O is a lever in operative contact with the wheel N and rigidly connected to the cam shaft II, and by which the said shaft H is turned.

P represents a pulley and bolt, by means of which the governor M is revolved.

is a weight attached to the lever it, which is in turn rigidly attached to the shaft H. This weight \V in part balances the weight of the governor M and wheel N.

fand f represent the springs which hold the latches b and b in their operative positions. g and g are stops which hold the said latches b and b from being thrown outward too far by the said springs f and f.

The action of the exhaust-valves, their actuating-links c dand c d, and the wrist-plate E is identical with the action of the corresponding parts of any similar valve-gear and need not be here described. No claim is here made to; originalityin this part of theapparains. r r

latch 13 about-theoenter ofthe valve-stem B,

admitting steam to the cylinder o'f the. engine.

In its inotionthccatchj is moved away from the centerof valve-stem Buntilitdisengagcs' the latoh b, whentlie weight'K, through the.

rod hand the crank-asuddenly turns the valve-stem I3 to its original position, asshown,

' 7 closingthevalve and cutting oii'steam from vgthe cylinder of theengine- As the motion of the wrist-plate :E continues the-catchy" is, V forced againstthciatch b, the spring f yield- I .inguntil, the wrist-plate E having reached thelimitof its motiomthe eatohj engageswith the latch Z). r 5 'lhcfaction on'thetvalve- .stemli is then the same as that of l3, just described;

The action of the governor is: as follows:

- As the speed of the engine increases and the governor-balls fiyoutward the wheel N is raisech This raises the lever'O, :whiohis rigidly attached totheeam-ehaftll; This turns ,thc cam-shaftll in such direction that the two cams G and G throw thefnlcrnmsland I inward. llhis increases the. motion of the V stroke; This action slows theen-gins to non in casethc speed becomes ire in al speed.

books ,7 andj, thn causing thci neto release the latches h and b at anearlier partof the dnced the Wheel N falls andinso doing turns the cam-shaft II in the opposite direction, throwing the fulcrums I and I outward and thus causing the hooks j and j to hold to the latches b and l) for a longer portion of the stroke. This raises the speed of the engine to its normal value.

In case of an abnormal increase of speed the hooks j and j will not engage the latches b and I), because of the fact that the levers J and J are lowered when the f ulcrums I and I are moved inward. Thus the steam will be entirely out off.

In case of breakage of the governor-driving cylinder as before.

BlftillOn 0f ill'venti d c e I claim is 7 V 7 r l. Ina steam-engine valvegear, the com bination with two'rotary steam-valves, of a 'wristplate, twolevers pivotally attached to the said wristqslate, two .IIIOVZLblG fnlcrnnis 2; In a steam-engine valve-gear, thei'coin-- bination with two rotary steam-valves, of two -n1echanisn1the. wheelN will dropsofzirthat r the lever 0 will be disengaged, and the weight WV will then, turn thecam-shaftll so as to throw the fnlcrnmsl andI" to their extreme. inward positions, cutting oft steani from the 1 in connection withcthe said lovers, the posi l tions of the saidfnlcrnms beinggovcrned by a centrifugal device,as set forth.

levers for. operating the said valves, two'mow able fulcrunis inconnection with the said he i vers, twocaniscontrolling the positions of the c said fulernms and meanswherebythecains 7'5 1 I '3; :In'asteam-enginmthe combination with the engine-cylinder, of awrist-plate .revolur are moved bya cen trif u gal device, as set forth.

bly connectedto the saidcylindeigtwo levers zpivotallycon nected' toitlie said wrist-platc, two rotary stearn-valves, latches rigidiycon nected to the stemsoi'the said valves ancllioolcs'oricatches on thesaid leversadapted 7 'to engage the said latches, substantially as set forth. i

In a'steani-cn gin e, the combination with" the cn'gincbylinder, of awrist-plate' rcvoln- I bly connectedtothe said cylinder, two levers pivotally connected to "the. said wrist-plate,

tworotary steam-valves, latches rigidly con nected to "the. stems of thesaid' valvcs,:hooks or catches on 'the's'aid levers adaptedto'eiv gage the said latches and two movable fulcrums in connection with the said lovers, the position of the said fulcrums being controlled by a centrifugal governor, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 8th day of February, A. D. 1896.

C. IV. CIIAIHVICK.

WVitnesses:

FRED B. COREY, GEO. C. HOUGHTON. 

